Adjustable flow probe

ABSTRACT

A flow probe has been described which includes a sensor housing and a coupling member. The sensor housing with one or more sensors mated together with the coupling member form the flow probe. The sensor housing accepts a variety of different sized coupling members to form flow probes of different sizes. The sensor housing is adapted to house one or more transducers. Additionally, a version of the flow probe includes strategically located positioning elements for ease in placement and retrieval of the flow probe.

TECHNICAL FIELD

[0001] The present invention relates to measurement devices and inparticular to flow probes and mechanisms for placement and removal ofimplantable medical devices.

BACKGROUND INFORMATION

[0002] Flow probes are used for measuring the flow of fluid within aconduit. There are many applications in clinical and research medicinein which measurement or estimation of fluid flow within a conduit isdesirable. For example, the monitoring of blood flow in a vesselprovides information that may be used in a variety of applications. Someof these applications include the discovery and assessment of compoundsduring the development of various drugs or assessing the hemodynamicstatus of patients for the purpose of guiding therapies or care. Anadditional application is the research of the various factors that mayimpact the hemodynamic status where the blood flow parameter is one ofthe indicators. For many applications implantable devices such as flowprobes are surgically implanted in animals or humans. The placement offlow probes and other implantable devices is a difficult task as thedevices are small and precision in placement is vital.

[0003] When placing flow probes for measurement of fluid flow within aconduit the orientation of the probe with respect to the conduit isessential. For example, some transit time measurement devices aredependent upon the angle of an ultrasound path with respect to fluidflow. Some flow probes completely encircle or partially encircle theconduit to be monitored and have to be sized properly so as to reducemeasurement errors. If the flow probe is not positioned properlymeasurement errors can result. For example, when a conduit is smallerthan the conduit size that a flow probe was designed for, the probe canrotate and/or tilt on the conduit, causing an error in the angle thatthe ultrasound beam intersects the fluid flow, resulting in an error inthe flow measurement.

[0004] Flow probes vary in size for the respective application.Currently, individual probes are designed to operate optimally on asingle conduit size to reduce the risk of measurement errors caused byultrasound angle tilting errors. As a result, probes of various sizesmust be produced to meet the wide range of applications. The end userhas to stock multiple sizes of probes to meet the range of anticipatedapplications, which is expensive for both the manufacturer and customer.

[0005] Accurate placement and, once implanted, proper orientation offlow probes may be difficult to accomplish. Retrieval of implanteddevices is also very difficult. Devices such as flow probes are oftenlocated in difficult to reach places and accessing the device forremoval becomes challenging. Improperly grasping a device with pincersor tweezers may damage the device. In the case of having a memory devicethat stores calibration or other information integral with the flowprobe, the memory device may be damage and information lost due toimproper handling with surgical instruments. In other scenarios thedevice may break up and pieces of the device may be lost within the bodycavity.

SUMMARY

[0006] The above mentioned problems with medical devices and flow probesare addressed by one or more embodiments of the present invention andwill be understood by reading and studying the following specification.

[0007] According to one aspect of the present invention an apparatus isprovided. The apparatus includes a sensor housing adapted for mountingone or more sensors. The apparatus further includes one of a pluralityof different sized coupling members which includes one or more windowsfor the one or more sensors. The sensor housing is adapted to couplewith the one of a plurality of different sized coupling members toaccommodate various sized conduits. In one embodiment, the sensor is atransducer and the windows are acoustically transparent windows. Othersensors may be used in the present sensor housing.

[0008] According to another aspect of the present invention a flow probeis provided. The flow probe includes one or more transducers and asensor housing adapted for mounting the one or more transducers. Theflow probe also includes one of a plurality of different sized couplingmembers which includes one or more acoustically transparent windows forthe one or more transducers. The sensor housing is adapted to couplewith the one of a plurality of different sized coupling members toaccommodate various sized conduits.

[0009] According to an alternate aspect of the present invention animplantable medical device is provided. The implantable medical deviceincludes a first body. The first body includes positioning elements,such as dimples, for placement and retrieval of the implantable medicaldevice.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010]FIG. 1 is an illustration of a flow probe according to oneembodiment of the present invention.

[0011]FIG. 2A is a side view of a flow probe constructed according toone embodiment of the present invention.

[0012]FIG. 2B is a side view of one embodiment of a tool for placementand retrieval of one embodiment of a closure mechanism.

[0013]FIG. 3 is a side view of a flow probe constructed according to oneembodiment of the present invention.

[0014]FIG. 4 is a side view of a flow probe constructed according to oneembodiment of the present invention.

[0015]FIG. 5A is an illustration of a flow probe constructed accordingto one embodiment of the present invention.

[0016]FIG. 5B is an illustration of a flow probe constructed accordingto one embodiment of the present invention.

[0017]FIG. 6A is an illustration of a flow probe constructed accordingto one embodiment of the present invention.

[0018]FIG. 6B is an illustration of a flow probe constructed accordingto one embodiment of the present invention.

[0019]FIG. 7 is an illustration of a flow probe constructed according toone embodiment of the present invention.

[0020]FIG. 8 is an illustration of a sensor housing for a flow probeconstructed according to one embodiment of the present invention.

[0021]FIG. 9 is an illustration of a flow probe and tool according toone embodiment of the present invention.

DETAILED DESCRIPTION

[0022] In the following detailed description, reference is made to theaccompanying drawings which form a part hereof, and in which is shown byway of illustration specific embodiments in which the invention may bepracticed. It is to be understood that other embodiments may be utilizedand structural changes may be made without departing from the scope ofthe present invention.

[0023]FIG. 1 is an illustration of an embodiment of a flow probe showngenerally at 100 and constructed according to the teachings of thepresent invention. The flow probe 100 includes a sensor housing 102which is adapted to mate or couple with a coupling member 104. Whenengaged, the outer surface 117 of the coupling member 104 fits snuglyagainst the inner surface 115 of the sensor housing 102.

[0024] The sensor housing 102 is adapted to hold one or more sensors. Inone embodiment, the sensor is a transducer. The sensor housing includesone or more connecting members 101 extending from the main body 125 ofthe sensor housing 102. The connecting members 101 engage with slots 110of the coupling member 104 in order to snugly fit the sensor housing 102together with the coupling member 104. In one embodiment, the slots 110also serve as windows for the one or more transducers.

[0025] In one embodiment, sensors 116 are secured by holders such as 108within the sensor housing 102. In one embodiment, the sensor housingaccommodates four sensors 116. The sensors are held in precise alignmentin order to perform transit-time measurements, flow velocitymeasurements, and volumetric fluid flow measurements. It is understoodthat other measurements may be performed without departing from thescope of the present invention. In one embodiment, the holders 108 alignthe one or more sensors for transit time measurement. In anotherembodiment, the holders 108, align the one or more sensors for pulsedoppler measurement. In a further embodiment, the holders align the oneor more sensors for continuous wave doppler measurement.

[0026] The coupling member 104 includes one or more windows. In oneembodiment, slots 110 also provide windows which are acousticallytransparent. Once the sensor housing 102 is coupled with the couplingmember 104 transducers 116 mounted within the sensor housing areoperable through the acoustically transparent windows in slots 110. Inone embodiment, the acoustically transparent windows comprise cut-outs.In one embodiment, the windows comprise a material which separates thesensors from the signal source and which allows the signal to passthrough with an acceptable amount of attenuation.

[0027] In one embodiment, the sensors 116 are ultrasound transducerswhich consist of piezoelectric crystals that convert electrical energyto high-power ultrasonic energy. In one embodiment, two crystals in apair are positioned opposing one another so that they have a commonfield of view. When mounted on a conduit, these crystalscontemporaneously transmit signals through the conduit to be received bythe opposite crystal. In another embodiment, two pairs of crystals areused with one crystal in each pair positioned opposing one another sothat they have a common field of view. When mounted on a conduit, thesecrystals transmit signals through the conduit to be received by anopposing crystal. The transducers may be located and/or aligned in anynumber of ways in order to achieve desired measurements such as transittime, pulse doppler, continuous wave doppler measurements. It isunderstood that other measurements are possible without departing fromthe scope of the present invention. It is also understood that thesensor housing is not limited to housing transducers. Furthermore, thenumber, type and operation of devices which are used may vary withoutdeparting from the scope of the present invention.

[0028] In one embodiment, the flow probe 100 includes a cable (notshown) which has an access 107. In one embodiment, the flow probe 100includes a housing release mechanism which allows the sensor housing 102to be released from the coupling member 104. The sensor housing 102 isremoved leaving the coupling member 104 behind.

[0029] In one embodiment, the housing release mechanism is a button,which, when depressed, releases sensor housing 102 from coupling member104. In one embodiment, the housing release mechanism is a release lock.In one embodiment, a tool is used to aid in the release of the sensorhousing 102 from the coupling member 104. The tool engages with thesensor housing 102 releases or detaches the sensor housing 102 from thecoupling member 104 and enables the sensor housing 102 to be removed.

[0030] It is understood that the housing release mechanisms may varywithout departing from the scope of the present system.

[0031] In one embodiment, the sensor housing 102 is made of a harderdurometer material than the coupling member 104. In another embodiment,the coupling member 104 is made of a flexible material which allows thecoupling member to conform to a conduit. In one embodiment couplingmember 104 and sensor housing 102 are made of the same material. Theconduit includes in vivo applications such as a blood vessel, an arteryand the like as well as application outside of a living organism such astubing, channels, tunnels and the like.

[0032] In one embodiment, flow probe 100 includes a closure mechanism106. The closure mechanism 106 allows flow probe 100 to be securelyclosed about a conduit.

[0033] In one embodiment, coupling member 104 includes a closuremechanism 106. The closure mechanism 106 combined with the couplingmember 104 provides an apparatus which encircles a conduit. The closuremechanism 106 also provides a stable placement of the sensors in thedevice with respect to the conduit. In one embodiment, the closuremechanism 106 and coupling member 104 are selected to conform as closelyas possible to the conduit without substantially deforming the conduitor restricting the lumen through which fluid is transported.

[0034] In one embodiment, the flow probe 100 is designed for use in vivoand one or more of the sensor housing 102, coupling member 104 and theclosure mechanism 106 are made of a biocompatible material.Biocompatible materials include materials which are Federal Drug Agency(FDA) or U.S. Pharmacopeia Class VI approved.

[0035] In another embodiment, one or more of sensor housing 102,coupling member 104, and/or closure mechanism 106 may be made of abiodegradable material. Biodegradable materials include absorbablesynthetic materials, bioabsorbable materials, polyglycolic acid materialand/or its copolymers, polyglactin acid material and/or its copolymers,biodegradable polymers or the like. These biodegradable materials allowone or more portions of the probe to decompose within a predeterminedtime frame.

[0036] In one embodiment, a sensor release mechanism is coupled tosensors 116. The sensor release mechanism allows sensors 116 to beremoved from sensor housing 102. In one embodiment, the sensor releasemechanism is coupled to the sensors and is used to remove the sensorsfrom sensor housing 102 while biodegradable portions such as sensorhousing 102 and coupling member 104 of probe 100 remain in vivo. In oneembodiment, this provides that the sensor release mechanism can betriggered from a location remote from the probe, allowing the one ormore sensors to be released from sensor housing 102. This allows thesensors to be removed from the patient without having to perform a majorsurgical procedure. In one application of this concept, thebiodegradeable portions of the probe biodegrade after approximately 30days. In one application the probe biodegrades after one week. Othertime frames are possible without departing from the scope of the presentsystem.

[0037]FIG. 2A is a side view in cross section of one embodiment of aflow probe shown generally at 200 and constructed according to theteachings of the present invention. Flow probe 200 includes a sensorhousing 202 and a coupling member 204. FIG. 2A illustrates the sensorhousing 202 and coupling member 204 coupled together. The flow probeincludes one or more transducers (not shown). Flow probe 200 includes aclosure mechanism 206 which is shown secured in place. In oneembodiment, closure mechanism 206 is designed with a notch closuremechanism and provides a positive closure. In one embodiment, closuremechanism 206 is shown with protrusions 220 which fit into notches 222on the coupling member 204.

[0038] In operation, one embodiment of closure mechanism 206 is snappedin place by inserting one of the two protrusions 220 into one of the twonotches 222 in the coupling member and then snapping the secondprotrusion 220 into the second notch 222. In one embodiment, closuremechanism 206 includes a receptacle 290 which receives a positioningtool 251 as shown in FIG. 2B. The tool is used to place the closuremechanism 206 in position with respect to the coupling member 204 and tosnap closure mechanism 206 into place. In one embodiment, the receptacle290 may aid in deforming the closure mechanism 206 to snap into place.

[0039] In another embodiment, closure mechanism 206 slides into placeusing the notches 222 as guides for the protrusions 220. Closuremechanism 206 is adapted to slide into coupling member 204 from the leftside of the coupling member 204 or from the right side of the couplingmember 204. Receptacle 290 is also useful for sliding closure mechanism206 into place using its mating positioning tool (not shown).

[0040]FIG. 3 is a side view in cross section of another embodiment of aflow probe shown generally at 300 and constructed according to theteachings of the present invention. Flow probe 300 includes a sensorhousing 302 and a coupling member 304 which are shown coupled together.Flow probe 300 also includes a closure mechanism 306. Closure mechanism306 is designed as a sliding closure mechanism and provides a positiveclosure.

[0041] In operation, one embodiment of closure mechanism 306 slides intoplace with the coupling member 304 to form a positive closure about aconduit. Closure mechanism 306 slides into place without the need fornotches on the coupling member to guide the closure mechanism. In oneembodiment, closure mechanism 306 includes extensions 359 which areshaped to conform to coupling member 304 and aid in sliding closuremechanism 306 in place. Closure mechanism 306 is adapted to slide intocoupling member 304 from the left side of the coupling member 304 orfrom the right side of the coupling member 304.

[0042] In another embodiment, closure mechanism 306 is snapped in placeby placing one of the two extensions 359 into place on the couplingmember 304 and then snapping the second extrusion 359 into place on thecoupling member 304. In one embodiment, closure mechanism 306 includes areceptacle 390 which receives a positioning tool (not shown) forplacement of the closure mechanism 306. In one embodiment, thereceptacle 390 may aid in deforming the closure mechanism 306 to snapinto place.

[0043]FIG. 4 is also a side view in cross section of another embodimentof a flow probe shown generally at 400 and constructed according to theteachings of the present invention. Flow probe 400 includes a sensorhousing 402 and a coupling member 404 which are shown coupled together.Flow probe 400 includes a closure mechanism 406. Closure mechanism 406is designed as a rotating closure and is secured at one end. Inoperation, closure mechanism 406 is secured in place at a first end 433using a hinge 456. In one embodiment, the closure mechanism is securedat first end 433 using a post. In one embodiment, the closure mechanismis secured at first end 433 using a screw. In one embodiment, theclosure mechanism is secured at first end 433 using a rivet. In oneembodiment, the closure mechanism is secured at first end 433 using aknob. Other securing apparatus and method may be employed withoutdeparting from the scope of the present invention. The first end 433 ofclosure mechanism 406 rotates about the hinge 456 and swings the secondend 435 into place to provide a positive closure.

[0044] It is understood that closure mechanism 106 of FIG. 1 is notlimited by closure mechanisms 206, 306 and 406 of FIGS. 2, 3, and 4,respectively. One of ordinary skill in the art understands that anynumber of closure mechanisms which provide a positive closure may besubstituted for these closures. In one embodiment, closure mechanism206, 306 and 406 each include a locking device (not shown) which allowsthe closure mechanism to lock into place. In one embodiment, closuremechanism 106 is omitted and flow probe 100 is secured to a conduit suchas a vessel using a tissue adhesive or other attaching means.

[0045]FIG. 5A is an illustration of one embodiment of a flow probeindicated generally at 500 and constructed according to the teachings ofthe present invention. Flow probe 500 includes a sensor housing 502 anda coupling member 504. In addition flow probe 500 includes one or moretransducers (not shown). FIG. 5A illustrates the sensor housing 502coupled together with coupling member 504. The sensor housing 502 isadapted to couple with a variety of different sized coupling members 504in order to form flow probes of selected sizes. The coupling members 504are interchangeable with the sensor housing 502. As shown in FIG. 5A,coupling member 504 has a thickness t1-1. As illustrated with the dashedlines the sensor housing is adapted to couple with a coupling member ofany appropriate thickness e.g. t2-1, t3-1. Other sizes and geometriesmay be used without departing from the scope of the present invention.

[0046] Thus, a single sensor housing 502 is adapted to couple with avariety of different sized coupling members 504 to accommodate varioussized conduits. In one embodiment, flow probe 500 includes a closuremechanism 506A to match a particular coupling member 504 to allow theflow probe to encircle a particular conduit. Another closure mechanism506B may also be used with a different sized coupling member 504 toachieve a close fit to a conduit. An accurate fit reduces movement ofthe apparatus about the conduit and may improve overall measurementaccuracy.

[0047]FIG. 5B shows one embodiment of a flow probe 500 with a particularcoupling member 504 attached to sensor housing 502 and a particularclosure mechanism 506. Different sized conduits may be accommodatedusing the different sized components, as demonstrated by FIG. 5B. Forexample, in one embodiment a conduit with an outer diameter ofapproximately ø₂ may be accommodated. In one embodiment, a conduit withan outer diameter of approximately ø₂ or smaller may be accommodated. Inone embodiment, a conduit with an outer diameter of approximately 75% ofø₂ to approximately 100% of ø₂ may be accommodated. It is understoodthat other sizes and shapes of coupling members and closure mechanismsmay be used without departing from the scope of the present invention.

[0048]FIG. 6A is an illustration of an embodiment of a flow probeindicated generally at 600 and constructed according to the teachings ofthe present invention. Flow probe 600 includes sensor housing 602,coupling member 604 and a closure mechanism 606. In addition flow probe600 includes one or more transducers (not shown). FIG. 6A illustratesthe sensor housing 602 coupled to coupling member 604. The sensorhousing 602 is adapted to couple with a variety of different sizedcoupling members 604 and closure mechanisms 606 in order to formdifferent sized flow probes. As shown in FIG. 6A, coupling member 604has a thickness t1-2. As illustrated with the dashed lines, the sensorhousing is adapted to couple with a coupling member of any appropriatethickness e.g. t2-2 and t3-2. For example, in one embodiment a conduitwith an outer diameter of approximately ø₂ may be accommodated. In oneembodiment, a conduit with an outer diameter of approximately ø₂ orsmaller may be accommodated. In one embodiment, a conduit with an outerdiameter of approximately 75% of ø₂ to approximately 100% of ø₂ may beaccommodated. In various embodiments, both the coupling member 604 andthe closure mechanism 606 vary in thickness and geometries toaccommodate various sized conduits, without departing from the scope ofthe present invention.

[0049]FIG. 6B demonstrates flow probe 600 with transducer housing 602with thickness t3-2. It is understood that other shapes and sizes may beused without departing from the scope of the present invention.

[0050]FIG. 7 is an illustration of an embodiment of a flow probeindicated generally at 700 and constructed according to the teachings ofthe present invention. Flow probe 700 includes sensor housing 702coupled to coupling member 704. In one embodiment, flow probe 700includes a closure mechanism (not shown) which provides the flow probepositive closure about a conduit. Flow probe 700 has positioningelements. The positioning elements include means for positioning theflow probe 700. One example of positioning elements includes a pair ofdimples 750 on the left face 786 and another pair of dimples (not shown)on the right face of coupling member 704. Dimples 750 are used to assistin placement and retrieval of the flow probe 700 or coupling member 704.A tool such as a clamp, tweezers, pincers, forceps or the like withprotrusions which mate with dimples 750 and the dimples not shown on theright face is used to pick up, place or retrieve a device such as flowprobe 700. In addition, the main body 725 of flow probe 700 has a firstset of dimples 752 and a second set of dimples (not shown) which assistin grasping the flow probe 700 for placement and retrieval of flow probe700. In this embodiment, the dimples are placed on surface 781 and on anopposing surface (not shown) to allow the flow probe to be grasped in aplurality of orientations. In other embodiments, the dimples are placedin pairs, in a radial set, and in rows. It is understood that otherpositioning elements may be used without departing from the scope of thepresent invention. For example, other dimple designs and placements maybe used without departing from the scope of the present invention. Thedimples are located so as to assist in grasping the flow probe 700 usinga tool such as a pair of forceps or a clamp with protrusions which matewith dimples 752 or 750.

[0051]FIG. 8 is an illustration of one embodiment of a sensor housingfor a flow probe indicated generally at 802 and constructed according tothe teachings of the present invention. The sensor housing 802 includesa pair of dimples 850 on the left face 881 and another pair of dimples(not shown) on the right face. In addition, sensor housing 802 includesa first radial set of dimples 852 on a first face 881 of sensor housing802 and a second radial set of dimples (not shown) on a second face ofsensor housing 802.

[0052] The dimples placed on sensor housing 802 mate with a tool whichallows the flow probe and its components to be picked up, placed andremoved with ease. In one embodiment, the tool attaches to any twoopposing pairs of dimples for grasping the flow probe, picking up,placing, retrieving sensor housing 802 and the like.

[0053]FIG. 9 is an illustration of one embodiment of a flow probe 900constructed according to the teachings of the present invention. Flowprobe 900 is illustrated with a tool 910 grasping sensor housing 902 ofprobe 900. (Note: The tool is not shown drawn to scale) Although FIG. 9shows the tool 910 grasping sensor housing 902 in a first example, it isnot limited to this attachment location. For example, tool 910 may graspdimples on the side of the sensor housing 902, as shown by example 910A.Another position of the tool 910 is shown at example 910B. Yet anotherexample is shown in example 910C. It is understood that in otherembodiments the positioning, number and type of dimples may vary withoutdeparting from the scope of the present invention. For example, thedimples may be placed on the sensor housing, the coupling member or boththe sensor housing and the coupling member. As a further example, inalternate embodiments, the dimples may be square or triangular in shape.As a further example, it is understood that an alternate tool forgrasping a flow probe may be employed and that neither the dimples northe tools shown are meant to be limiting. For example, slots, grooves,bumps and the like may be used to mate with a tool for placement andretrieval of the flow probe and its components. In one embodiment, thetool is also designed to attach to and release the sensor housing fromthe coupling member. This allows retrieval of the sensor housing withtransducers and leaves the coupling member with closure mechanism inplace.

[0054] It is understood that in different embodiments positioningelements may be located on one or more of the sensor housing, thecoupling member, and the closure mechanism. Different combinations ofplacement of the positioning elements are possible without departingfrom the scope of the present teachings. In one embodiment, the closuremechanism is positioned using positioning elements. In one embodiment,the coupling member is positioned using positioning elements. In oneembodiment, the coupling members are interchanged using positioningelements and tools as demonstrated in the present patent application. Inone embodiment, the closure mechanism is positioned, inserted or removedusing tools according to the teachings of the present patentapplication. One aspect of positioning elements and tools on the variouscomponents allows for positioning and assembly of the flow probe whilein the body. The different positioning elements discussed herein may beused in various combinations without departing from the scope of thepresent description.

[0055] The sensor housing, flow probes and components of flow probesillustrated in FIGS. 1-9 are not meant to be exhaustive. One of ordinaryskill in the art will understand that the flow probes and components maybe of any size, shape and/or style appropriate for a particularapplication. In one embodiment, a flow probe which completely encirclesa conduit is used. In another embodiment, a flow probe which partiallyencircles a conduit is used. In an alternate embodiment, a flow probewhich conforms to the shape a conduit and either completely encircles orpartially encircles the conduit is used.

CONCLUSION

[0056] An apparatus which includes a sensor housing adapted for mountingone or more sensors has been described. The apparatus further includesone of a plurality of different sized coupling members which includesone or more acoustically transparent windows for the one or moretransducers. The sensor housing is adapted to couple with one of theplurality of different sized coupling members to accommodate varioussized conduits.

[0057] In addition, a flow probe has been described. The flow probeincludes one or more transducers and a sensor housing adapted formounting the one or more transducers. The flow probe also includes oneof a plurality of different sized coupling members which includes one ormore acoustically transparent windows for the one or more transducers.The sensor housing is adapted to couple with the one of a plurality ofdifferent sized coupling members to accommodate various sized conduits.

[0058] Further an implantable medical device has been described. Theimplantable medical device includes a first body. The first bodyincludes strategically located dimples for placement and retrieval ofthe implantable medical device.

[0059] Although specific embodiments have been illustrated and describedherein, it will be appreciated by those of ordinary skill in the artthat any arrangement which is calculated to achieve the same purpose maybe substituted for the specific embodiment shown. For example, one ofordinary skill in the art would understand that dimples could be usedwith any other appropriate implantable device, e.g., a transmitter, acatheter, a pacemaker or defibrillator and the like. This application isintended to cover any adaptations or variations of the presentinvention. Therefore, it is intended that this invention be limited onlyby the claims and the equivalents thereof.

What is claimed is:
 1. An apparatus, comprising: a sensor housing adapted for mounting one or more sensors; one of a plurality of different sized coupling members which includes one or more windows for the one or more sensors; and wherein the sensor housing is adapted to couple with the one of a plurality of different sized coupling members to accommodate various sized conduits.
 2. The apparatus of claim 1, wherein the sensor housing comprises a main body and at least one connecting member extending from the main body, wherein each of the at least one connecting members is adapted to hold the one or more sensors.
 3. The apparatus of claim 1, wherein the one of a plurality of different sized coupling members conforms to a conduit.
 4. The apparatus of claim 2, wherein the main body of the sensor housing includes a housing release mechanism, wherein the housing release mechanism is adapted to detach the sensor housing from the coupling member once they are coupled together.
 5. The apparatus of claim 1, further comprising a closure mechanism coupleable to the one of a plurality of different sized coupling members.
 6. The apparatus of claim 5, wherein the sensor housing, the one of a plurality of different sized coupling members, and the closure mechanism are each made of a biocompatible material.
 7. The apparatus of claim 6, wherein the sensor housing, the one of a plurality of different sized coupling members, and the closure mechanism are each made of a biodegradable material.
 8. The apparatus of claim 7, further comprising a sensor release mechanism for releasing the one or more sensors from the sensor housing, wherein the one or more sensors are removable leaving the biodegradable material in vivo.
 9. The apparatus of claim 1, wherein the sensor housing is made of a harder durometer material than the one of a plurality of different sized coupling members.
 10. The apparatus of claim 2, wherein the main body of the sensor housing includes positioning elements to aid in placement and retrieval of the sensor housing.
 11. The apparatus of claim 10, wherein the positioning elements comprise a first array of dimples and a second array of dimples.
 12. The apparatus of claim 11, wherein the first array of dimples and the second array of dimples comprise a circular pattern.
 13. The apparatus of claim 10, wherein the main body of the sensor housing further includes a housing release mechanism, wherein the housing release mechanism is adapted to detach the sensor housing from the coupling member once they are coupled together.
 14. The flow probe of claim 10, wherein the one or more sensors are one or more ultrasound transducers and the one or more windows are acoustically transparent.
 15. The flow probe of claim 14, wherein the one or more transducers comprise one or more piezoelectric transducers.
 16. The flow probe of claim 1, wherein the one or more sensors are ultrasound transducers and the windows are acoustically transparent.
 17. An apparatus, comprising: a coupling member for a flow probe, wherein the coupling member is adapted to mate with a sensor housing for a flow probe, wherein the sensor housing is adapted for mounting one or more sensors; and wherein the coupling member includes one or more windows for the one or more sensors.
 18. The apparatus of claim 17, further comprising a closure mechanism coupleable to the coupling member.
 19. The apparatus of claim 18, wherein the coupling member and the closure mechanism are made of a biocompatible material.
 20. The apparatus of claim 18, wherein the coupling member and the closure mechanism are made of a biodegradable material.
 21. The apparatus of claim 17, wherein the one or more windows are transparent to the one or more sensors.
 22. A sensor housing for a flow probe, comprising: a main body adapted to mate with one of a plurality of different sized coupling members to accommodate various sized conduits; at least one connecting member extending from the main body, each of the at least one connecting members is adapted to hold one or more sensors; and wherein the one of a plurality of different sized coupling members includes one or more windows for the one or more sensors.
 23. The sensor housing of claim 22, wherein the main body and the at least one connecting member are each made of a biocompatible material.
 24. The sensor housing of claim 22, wherein the one or more sensors are one or more transducers and the one or more windows are acoustically transparent.
 25. An apparatus, comprising: a sensor housing adapted for mounting one or more sensors; two or more coupling members, wherein each of the two or more coupling members includes one or more windows for the one or more sensors; and wherein the sensor housing is adapted to couple with the two or more coupling members to accommodate various sized conduits.
 26. The apparatus of claim 25, further comprising a closure mechanism coupleable to at least one of the two or more coupling members to provide a positive closure.
 27. The apparatus of claim 26, wherein the sensor housing, the two or more coupling members, and the closure mechanism are each made of a biocompatible material.
 28. The apparatus of claim 27, wherein the two or more coupling members are made of a biodegradable material.
 29. The apparatus of claim 25, wherein the one or more sensors are transducers and the one or more windows are acoustically transparent.
 30. A method for measuring flow in a lumen defined by a conduit with an outer diameter and cross sectional shape, comprising: selecting a coupling member, the coupling member conforming to the outer diameter and the cross sectional shape of the conduit; assembling the coupling member and a sensor housing; and positioning the coupling member and sensor housing adjacent the conduit.
 31. The method of claim 30, further comprising: selecting a closure mechanism, the closure mechanism conforming to the outer diameter and cross sectional shape of the conduit; and attaching the closure mechanism to the coupling member to encircle the conduit.
 32. The method of claim 30, further comprising: positioning the coupling member using a positioning tool.
 33. The method of claim 31, further comprising: positioning the coupling member using a positioning tool.
 34. An apparatus, comprising: one or more components of a flow sensor positioning elements for positioning the one or more components of the flow sensor, the positioning elements providing a positive grip on the one or more components for placement and positioning of the one or more components.
 35. The apparatus of claim 34, wherein the positioning elements are dimples.
 36. The apparatus of claim 34, wherein the positioning elements are grooves.
 37. The apparatus of claim 34, wherein the positioning elements are slots.
 38. The apparatus of claim 34, wherein the positioning elements are on a sensor housing.
 39. The apparatus of claim 34, wherein the positioning elements are on a coupling member.
 40. The apparatus of claim 34, wherein the positioning elements are on a closure mechanism. 